Add "files_changed" and "msgpack_version_check" to NEWS.

NEWS

@@ -1,4 +1,6 @@
 2.1.3.dev0
+ * #1175: Add a "files_changed" option for customizing Borg's file modification detection.
+ * #1175: Add a "msgpack_version_check" option to prevent Borg from validating msgpack's version.
  * #1218: Add a "config show" action to display computed borgmatic configuration as YAML or JSON,
    handy for fetching borgmatic configuration from external scripts. See the documentation for more
    information:

borgmatic/config/schema.yaml

@@ -172,8 +172,9 @@ properties:
         description: |
             Threshold for considering a file as changed. See
             https://borgbackup.readthedocs.io/en/stable/usage/create.html for
-            details. Defaults to "ctime" (i.e., a file is considered
-            changed if its ctime has changed since the last backup).
+            details. Defaults to "ctime". E.g., a file is considered changed if
+            its ctime has changed since the last backup. (This option is
+            supported for Borg 1.4.2+ only.)
         example: ctime
     files_cache:
         type: string
@@ -574,9 +575,9 @@ properties:
     msgpack_version_check:
         type: boolean
         description: |
-            Optionally disable the msgpack version check.
-            Default is true; use at your own risk.
-        example: true
+            Optionally disable the msgpack version check. Default is true; use
+            at your own risk. (This option is supported for Borg 1.4.2+ only.)
+        example: false
     extra_borg_options:
         type: object
         additionalProperties: false